Gas leak postpones space shuttle Discovery launch

Marcia Dunn

Published
7:00 pm CDT, Tuesday, March 10, 2009

CAPE CANAVERAL, Florida - NASA postponed the launch of space shuttle Discovery just hours before it was to head to the international space station Wednesday because of a hydrogen gas leak that could have been catastrophic at liftoff.

The leak was in a different part of the system that already has caused a vexing one-month delay.

Shuttle managers put off the launch until Monday but left open the possibility that the repair work might allow for an attempt Sunday.

The latest delay means Discovery’s two-week flight must be shortened and some spacewalks cut out of the mission. That’s because Discovery needs to be gone from the space station before a Russian Soyuz rocket blasts off March 26 with a fresh station crew.

If Discovery isn’t flying by Monday - possibly Tuesday, stretching it - then it will have to wait until April.

Mission Control radioed the news to the three space station residents Tuesday evening. Commander Mike Fincke took it in stride, saying he’d rather see the shuttle this month than next.

“But more importantly, we’d rather see it up safely, so we understand,” he said.

The gaseous hydrogen began leaking just as the launch team was close to wrapping up the loading of Discovery’s external fuel tank for a late night liftoff. The seven astronauts had yet to board the spaceship.

Discovery’s flight to the space station is already late because of concern about hydrogen gas valves in the ship’s engine compartment. NASA spokesman Allard Beutel said Wednesday’s small leak was in plumbing outside Discovery, in the vicinity of the fuel tank and a hydrogen gas-venting line, and had nothing to do with the valves. But it still could have been dangerous at liftoff.

“When you’re launching, you have pyrotechnics going off,” said another NASA spokesman, Steve Roy. “You can’t have hydrogen leaking out in the vicinity of a launch pad … it’s possible it could explode.”

Discovery’s liftoff originally was targeted for mid-February, but concern about the shuttle’s three hydrogen gas valves resulted in four delays.

Shuttle managers said they’re convinced after extensive testing that the valves are safe and won’t break like one did during the last shuttle launch in November. The valves are part of the main propulsion system and control the flow of hydrogen gas into the fuel tank in order to maintain proper tank pressure.